popupMenu: Use less ambiguous symbols for radio options
- new checked and unchecked dot ornament assets
- updated JS with a NO_DOT ornament state, replaced instances of NONE with this
- adjusted so popup-ornamented-menu-item class is used only to for checkmark ornament
A bit of a follow-up from looking at #6961 (closed) where I realized the empty space was an ambiguity.
Edited by Sam Hewitt